Paul is rebuking his readers for their behavior. It appears that the Christians in Corenth were behaving like any other fallen person, they were self-centered. They were using the "Sunday resurection celebrations" as an opportunity to gorge on the community meal and even get drunk.
In this passage, Paul is instructing the believers on the significance of the Lord's Supper and exhorting them to honor Christ. The proclamation is by the believers, through their actions, to the world. The spiritual meal by which our souls (not bodies, as is pointed out in this passage) are fed proclaims to all creation that Jesus Christ is Lord; he is Messiah; his sacrifice is sufficient.